On Android, download Televizo, OTT Navigator or IPTV Smarters. Enable "Skip battery optimizations", otherwise the system may kill the application while browsing.
On iOS, choose GSE Smart IPTV or nPlayer. They support PiP and AirPlay. To limit traffic, go to the Settings application and select a 720p profile for mobile Internet, and 1080p for Wi-Fi only.
If a child uses the application, set up a PIN for sections 18+. Most clients have a Parental Control menu where you can hide categories or require a password before switching.